This application requests continued support for the NIEHS Center at the University of Texas Medical Branch. The mission of this Center is to integrate, coordinate and foster interactions and collaborations among a group of established investigators pursuing research pertinent to the effects of environmental factors on human health. The proximity to sources of many significant environmental problems, such as ozone pollution, emissions of fine particulates, hazardous chemical releases, hazardous waste sites, and pediatric lead exposure, makes UTMB a compelling site for a multidisciplinary environmental health sciences center. During the nine years of its existence, this Center has emerged as a national leader in elucidating cellular response mechanisms to environmental challenge and in working with the community to enhance awareness of environmental health issues and elaborate prevention and intervention strategies. The overarching theme of the UTMB NIEHS Center is the role of oxidative stress in mediating the health effects of exposure to environmental factors. Center investigators are aided by four service cores (Molecular Genetics, Biomolecular Resource Facility, Cell Biology, and Synthetic Organic Chemistry), which provide advanced technologies, unique reagents, and specialized expertise, as well as cost-effective and efficient access to more routine services or research materials. Scientific findings from the Center are communicated to the public through a vibrant COEP with advice from a Community Outreach Board.